The Pupil Light Reflex in Leber's Hereditary Optic Neuropathy: Evidence for Preservation of Melanopsin-Expressing Retinal Ganglion Cells

Author(s):Show less -

Moura, Ana Laura A. ^{[1, 2]} ; Nagy, Balazs V. ^{[1, 2, 3]} ; La Morgia, Chiara ^[4] ; Barboni, Piero ^[5] ; Fernandes Oliveira, Andre Gustavo ^{[1, 2]} ; Salomao, Solange R. ^[6] ; Berezovsky, Adriana ^[6] ; de Moraes-Filho, Milton Nunes ^[6] ; Chicani, Carlos Filipe ^[7] ; Belfort, Jr., Rubens ^[6] ; Carelli, Valerio ^[4] ; Sadun, Alfredo A. ^[7] ; Hood, Donald C. ^{[8, 9]} ; Ventura, Dora Fix ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Inst Psicol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Nucleo Neurociencias & Comportamento, Sao Paulo - Brazil

^[3] Budapest Univ Technol & Econ, Dept Mech Opt & Eng Informat, Budapest - Hungary

^[4] IRCCS Ist Sci Neurol Bologna, Bologna - Italy

^[5] Studio Oculist Azeglio, Bologna - Italy

^[6] Univ Fed Sao Paulo UNIFESP, Escola Paulista Med, Dept Oftalmol, Sao Paulo - Brazil

^[7] Univ So Calif, Keck Sch Med, Dept Ophthalmol, Doheny Eye Inst, Los Angeles, CA 90033 - USA

^[8] Columbia Univ, Dept Psychol, New York, NY 10027 - USA

^[9] Columbia Univ, Dept Ophthalmol, New York, NY 10027 - USA

• Document type: Journal article
• Source: INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE; v. 54, n. 7, p. 4471-4477, JUL 2013.
• Web of Science Citations: 44

Abstract

PURPOSE. To investigate the pupillary light reflex (PLR) of patients with severe loss of vision due to Leber's Hereditary Optic Neuropathy (LHON) in the context of a proposed preservation of melanopsin-expressing retinal ganglion cells (mRGCs). METHODS. Ten LHON patients (7 males; 51.6 +/- 14.1 years), with visual acuities ranging from 20/400 to hand motion perception and severe visual field losses, were tested and compared with 16 healthy subjects (7 males; 42.15 +/- 15.4 years) tested as controls. PLR was measured with an eye tracker and the stimuli were controlled with a Ganzfeld system. Pupil responses were measured monocularly, to 1 second of blue (470 nm) and red (640 nm) flashes with 1, 10, 100, and 250 cd/m(2) luminances. The normalized amplitude of peak of the transient PLR and the amplitude of the sustained PLR at 6 seconds after the flash offset were measured. In addition, optical coherence topography (OCT) scans of the peripapillary retinal nerve fiber layer were obtained. RESULTS. The patient's peak PLR responses were on average 15% smaller than controls (P < 0.05), but 5 out of 10 patients had amplitudes within the range of controls. The patients' sustained PLRs were comparable with controls at lower flash intensities, but on average, 27% smaller to the 250 cd/m(2) blue light, although there was considerable overlap with the PLR amplitudes of control. All patients had severe visual field losses and the retinal nerve fiber layer thickness was reduced to a minimum around the optic disc in 8 of the 10 patients. CONCLUSIONS. The PLR is maintained overall in LHON patients despite the severity of optic atrophy. These results are consistent with previous evidence of selective preservation of mRGCs. (AU)

• FAPESP's process: 08/58731-2 - Vision as a sensitive indicator of conditions threatening retinal and central nervous system function
• Grantee: Dora Selma Fix Ventura
• Support Opportunities: Research Projects - Thematic Grants